Lecture 7 Flashcards
Pituitary gland
Pituitary gland 2
Pituitary gland 3
Gonadotropic hormones-general
- FSH and LH pituitary hormones gonadotropins;
- Produced under the GnRH hypothalamic control;
- Biochemical carbohydrate rich glycoproteins substances ;
- Presents two fractions, α (common) and β (specific), with a higher concentration of sialic acid;
- Sialic acid has a protective role, gives “personality” of hormones.
- Degranulation release under the cyclic AMP and Ca + +action ;
- Their inactivation is the liver & kidneys;
- They are produced and released together in
- different reports;
- Similar mechanisms of action;
- They have membrane receptors.
FSH (follicle stimulating hormone)
FSH (follicle stimulating hormone) ROLE
- In combination with estrogens:
- cell division & stimulate protein synthesis;
- stimulates plasminogen activity from the follicular fluid .
- Females:
- Anestrus therapy, the anovulatory heat and / or silent heat;
- - Poliovulation
- induce superovulation
- Indications
In males:
- -stimulation of Sertoli cells activity;
- -stimulation RNA & protein synthesis
LH (luteinizing hormone)
LH Secretion occurs in two ways:
tonic (Males & females), the level hovering around 1 ng LH / ml blood, even lower in
the XI-XIII days of the sexual cycle;
cyclic (females only), beginning at 6 h of the onset of heat and precedes ovulation by
24 h, lasting ≈ 7.4 h.
LH concentration may increase by 20-30 times (<25 ng LH / ml blood), maximum
(preovulator) being reached in the twentieth day of the sexual cycle.
LH (luteinizing hormone) Role & effects
LH (luteinizing hormone) Role & effects (2)
Prolactin (LTH-luteotrophic hormone)
- *Prolactin secretion is regulated by:
1. hypothalamus, which produces:**
LTH releasing hormone secretion-prolactoliberin effect;
LTH inhibiting hormone/ inhibits secretion-prolactostatin;
- *2. Dopamine, by acting as an inhibitor of LTH secretion;
3. Heredity.**
LTH (prolactin) in females
LTH (prolactin) in males
Placental lactogen
PMSG (Pregnant mare serum gonadotropin)
Biosynthesis
It is produced by endometrial cups in pregnant mares;
Dynamics of secretion:
Begins 30-40 days of gestation;
Increases between 50-70 days;
Decreased to Day 100;
Optimal blood samples between days 50 & 120
PMSG (Pregnant mare serum gonadotropin) ROLE:
Recommendations:
Heat induction and synchronization;
Super ovulation;
Ovarian inactivity.
HCG (Chorionic gonadotropin)
HCG (Chorionic gonadotropin) ROLE:
Recommendations:
- Anovulatory heat
- Prolonged heat;
- Delayed ovulation
- Ovarian cyst;
- Lutheal failure (preventing abortions);
- Hypo-or a galactia;
- Cryptorchidism.
